1. Field of the Invention
The present invention relates to an apparatus of polymer web by electrospinning process and manufacturing method thereof, and more particularly, to an apparatus of polymer web by electrospinning process and manufacturing method thereof, which can manufacture porous polymer web using an electrospinning method.
2. Description of the Related Art
In conventional fiber manufacturing skills, i.e., melt spinning, wet spinning, dry spinning and dry-jet wet spinning, fibers are manufactured by mechanically extruding and discharging a polymer melt or a polymer solution through nozzles and coagulating or solidifying it.
The fibers having several to several tens xcexcm diameter can be manufactured, using the conventional process. Presently, ultra-fine threaded fibers of sub-micron to several xcexcm diameters can be manufactured with only special polymers and manufactured by a very complex and restricted process using a method of dissolving a portion of the fibers.
Recently, it has been reported that an electrospinning process can adapt various kinds of polymers, such as polymer melt, polymer solution or the likes and manufacture fiber of several nanometer diameter.
Such fiber of small diameter is very high in a ratio of surface area to volume in comparison with the conventional fiber, makes the manufacture of film of high porosity possible, and can provide a new physical property not shown in the conventional products.
As the related report, xe2x80x9cElectrospinning process and applications of electrospun fibers (J. Electrostatics, 35, 151-160 (1995)) by Doshi and Reneker is disclosed. In U.S. Pat. No. 6,106,913 by Frank, it is disclosed that very fine fiber of 4 xc3x85xcx9c1 nm can be manufactured by combining the electrospinning process and an air vortex spinning technique. In U.S. Pat. No. 6,110,590, it is disclosed that biodegradable silk of 2 to 2000 nm diameter can be manufactured by using the electrospinning process.
Moreover, the electrospinning process is very simple, compared with the conventional methods, because directly manufacturing polymer web in a liquid state.
As polymers capable of being used in the electrospinning process, there are poly(vinylidenefluoride) (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene), polyacrylonitrile, poly(acrylonitrile-co-methacrylate), polymethylmetha crylate, polyvinylchloride, poly(vinylidenechloride-co-acrylate), polyethylene, polypropylene, nylon series such as nylon12 and nylon-4,6, aramid, polybenzimidazole, polyvinylalcohol, cellulose, cellulose acetate, cellulose acetate butylate, polyvinyl pyrrolidone-vinyl acetates, poly(bis-(2-methoxy-ethoxyethoxy)) phosphazene(MEEP), poly(ethylene imide) (PEI), poly(ethylene succinate), poly(ethylene sulphide), poly(oxymethylene-oligo-oxyethylene), poly(propyleneoxide), poly(vinyl acetate), polyaniline, poly(ethylene terephthalate), poly(hydroxy butyrate), poly(ethylene oxide), SBS copolymer, poly(lacticacid), polypeptide, biopolymer such as protein, pitch series such as coal-tar pitch and petroleum pitch. Copolymers and blends of the above polymers may be used. Also, it is possible to use blends in which emulsions or organic or inorganic powders are blended in the above polymers.
However, the electrospinning process largely depends on the intensity of electric charge, differently from the conventional similar processes, such as electric coating, discharging by adding the intensity of electric charge to external physical power. Thus, it is very important that many nozzles are concentrated and used in a small area and each nozzle is controlled precisely to manufacture web made of fiber of fine diameter because one nozzle is restricted in increasing a discharge amount and productivity.
Especially, it is very important to concentrate several capillary nozzles on one spinning pack and discharge in large quantities. If the nozzles are simply arranged and used, since fibrous polymer stream discharged from each nozzle have electric charge, the fibrous polymer streams push to each other by a mutual interference and get out of an area of a collector. Furthermore, the nozzles perform non-uniform discharge because of different environments of capillary nozzles, and thereby it is difficult to manufacture a film of a uniform thickness.
Many reports of action of organic solution having electric charge have been known, but the electrospinning process using the polymers began to develop recently. Although the porous polymer web manufactured by the electrospinning method have various merits as described above, techniques to manufacture the polymer web in a high speed and large quantities have not been developed.
Especially, devices of a laboratory scale using one needle for experimentation can be easily constructed, and thereby it is possible to manufacture in a small quantity. However, for common use, mass production must be realized.
It is, therefore, an object of the present invention to provide an apparatus of polymer web by electrospinning process and manufacturing method thereof, which can manufacture porous polymer web having a high porosity and an excellent productivity by the way of an electrospinning process by polymers solutions or melts.
To achieve the object, the present invention provides an apparatus of polymer web by electrospinning process including: a barrel storing at least one or more kinds of polymer materials in a liquid state; a pump pressurizing and supplying the polymer materials of the liquid state stored in the barrel; a spinning part for injecting the polymer materials of the liquid state supplied by the pump through at least one or more charged nozzles and manufacturing thin fibers; a first high voltage generator providing electric charge for charging the polymer materials discharged through the nozzles of the spinning part to have one polarity; and a collector for piling and transferring the thin fibers to form the polymer web, the fibers being charged to have a polarity opposed to the polarity of the spinning part and discharged by the nozzles.
In another aspect, to achieve the object, the present invention provides a method for manufacturing polymer web by electrospinning process including the steps of: making, pressurizing and supplying at least one or more kinds of polymer materials in a liquid state; and discharging and piling the polymer materials to a collector through one or more charged nozzles, the collector being located under the nozzles and charged to have a polarity opposed to the polarity of the charged nozzles, the collector moving in a prescribed speed.